The detection of compounds containing cyclic rings and nitrogen atoms can be desirable for a variety of applications. For example, nitroaryl-containing compounds are used in many relatively dangerous products such as, for example, pesticides, explosives, and the like. The detection of nitroaryl-containing compounds can be useful, for example, in locating land mines, searching for explosive materials at security checkpoints, analyzing pesticide levels at clean-up sites, and the like. Determination of such compounds can pose several challenges. For example, it can be difficult, in some instances, to determine the quantity and/or identity of such compounds while maintaining the safety of the person making the measurement. In addition, real-time determination can be difficult, with chemical analyses often requiring complicated, time-consuming, and expensive laboratory procedures.